Turntable drive



May 20, 1941. F. H. FODOR TURNTABLE DRIVE Filed Jan. 2, 1940 INVENTOR.

Patented May 1941 s PATENT OFFICE I TURNTABLE DRJVE a Ferenz H. Fodor, Los Angeles, Calif.,- assignor to Regan-Day, Inc., Los Angeles, Calif., a. corporation of California Application January 2, 1940, Serial No. 312,179

3 Qlaims. (Cl. 192-9) This invention pertains to improvements in turn-tab1es adapted for use in recording and reproducing machines or in other devices wherein it is desired to rapidly and positively start and stop a rotatable member such as a turn-table.

The device of the present invention has a large number of uses which will occur to those skilled in the arts. An example of one use shall be given. During the. presentation of plays, particularly during broadcasting, it is highly desirable to in- '10 troduce various sound effects at appropriate moments. Very often such effects are gathered from separate phonographs or phonographic recordings. Attempts have been made to place all sound effects which are to be used during the presentathe entire presentationof the play, then a single 0 record can not carry all of the desired sound effects and the silent groove noise may be sufficient to disturb the actors and make itself audible to the audience. It is therefore highly desirable ing a motor II carried or coupled to a drive shaft 1 2 journaled within the standard by a bearing I3. The drive shaft I2 is directly connected to a rigid circular member I4 which may be in the form of a spider or disc. A disc-shaped member I4 is shown in the drawing, the upper surface of such disc'carrying electromagnetic coils I5 circularly arranged on the disc. These coils may clutch coils I The .device is provided with a freely revolvable floating tum-table I6 which, in this particular form of the invention, is mounted on a spindle I1, said spindle being freely journaled in the shaft I2 and member I4.

An armature plate or plates I9 is suspended immediately above the electromagnetic coils I5. The armature plate I9 may be in the form of an annular ring and may be attached to the turntable I 6 by means of a resilient member I8. The member I8 may be in the form of a very thin, relatively flexible and resilient disc or it may be in the form of a spider provided with resilient be termed spring-like arms. This construction should perto have a single recordbearing the various sound efiects, such sound effects being separated by only a very short length of silent groove and that means he provided whereby the record may be brought up to proper reproducing speed instantaneously and stop instantaneously. This can be accomplished by the device of this invention.

An object-of the present invention, therefore, is to disclose and provide means for controlling the operation of a turn-table.

A further object is'to disclose and provide a mit the armature plate I 9 .to move vertically into and out of contact with the=electromagnetic coils J rality of solenoids or electromagnetic coils 20, each of these being adapted to actuate a linkage including a lever 2I pivoted at 22, said lever be- Mounted upon the outer periphery of said housing is a plu-j ing operably connected as by link 23 to a brake shoe 24. These brake shoes 24 are adapted to act upon the inner surface of a downwardly exturn-table drive and system whereby the turn- Fig, 1 is a vertical section of one form of device embodying the elements of the invention.

Fig. 2 is a wiring diagram for use in the device shown in Fig. 1.

As shown in Fig. 1, the device may comprise any suitable frame, support or base I0 contain- 5 tending lip formed in the turn-table I6.

. Current is supplied to the coils I5 carried by the rotatable member I4 by means of suitable brushes 25' and 26 cooperating with the commutator rings 21 and 28 carried by the lower sur face of the member I4. By referring to Fig. 2, it will be seen that currectly to the motor II and the line 30 is "connected to the brush contact 26 which cooperates with commutator 28 and thereby supplies energy I to the clutch coils I5. The return line includes the commutator ring-21, brush 25 and the line 32 leading to terminal 34 of a double throw switch, generally indicated at 33. The switch 1 arm 35 connected to line 3| may close the circuit with terminal 34 or with terminal 35 of the double throw switch 33. .Terminal 36 is connected by line 3! with the brake coils 20, the

5 rent from supply lines 30 and 3I- is supplied direturn line being indicated at as and connecting her and concentric therewith, electromagnetic coils carried by said member: an armature plate resiliently attached to said turn-table, said plate turn-table II, on the other hand, is made of light material so as to have a very low moment of inertia. Ordinarily, the circuit through the brake coils 20 may be closed by the double throw switch ll so as .to make certain that the tumtable does not revolve. If, however, such switch I8 is actuated so as to close the circuit leadin to theclutch coils itthe coils ii are energized and draw thearmature I! into flrm contact with the cores of the electromagnets, thereby coupling the turn-table II to the rotating member ll. The rotational speed of the member II is thus. instantaneously transmitted to the turn- 7 table I and reproduction of the record may take place immediately without distortion of the sound recorded upon the record carried by the tumtable. when it is desired to stop the turn-table,

the switch a is actuated so as to open the circuit to the clutch coils II and to close the circuit to the brake coils 20. These brake coils are thus immediately energized and operate the linkage including elements it and 23, pressing the brake shoes 24 against the rim of the turn-table and immediately stopping the turn-table. Since the clutch coils II are deenergized, the armature II is liberated from contact with the cores of the electromagnets byreason of the spring suspension I l so that the turn-table be-v comes freely floating' at the instant that the brake coils 2| are energized.

Although one particular embodiment of the invention has been described. it will be evident tothose skilled in the art that numerous changes ducing devices and the like the combination of:

a supporting base, a vertical drive shaft Journaled in said base, means for continuously driving said shaft, a rigid-circular member :11 unted on said shaft for rotation therewith, a reely revolvable floating turn-table above said membeing out of. contact with said coils when said coils are deenergized. and adapted to contact said coils whensaid coils are energized; stationary brake coils attached to the supporting base, brake shoes in operative relation to said turn-table,

supportingbase, a vertical drive shaft loumaled in said base, means for continuously driving said shaft, a rigid circular member mounted on said shaft for rotation therewith, said member havinga relatively high moment of inertia, a freely revolvable floating turn-table above said member and concentric therewith, said turn-table having a low moment of inertia, electromagnetic coils carried by said member; an armature plate resiliently attached to said turn-table, said plate be.- ing out of contact with said coils when said coils are deenergized and adapted to' contact said coils when said coils are energized; stationary brake coils attached to the supporting base, brake shoes inoperative relation to said turn-table, means connecting said brake coils and brake shoesfiand a circuit including a source of energy and a double throw switch whereby said brake coils are deenergized when said electromagnetic coils are energized, and the latter are deenerslzed'before-the brake coils are energized.

3. In a device of the! character described, the

tinuously driving said shaft, a rigid circular member mounted on said shaft for rotation therewith, a freely revolvable floating turn-table above could be made in'the form of the device, in the i said member and concentric therewith,- electromagnetic coils carried by said member, means for supplying electrical energy to said coils; an armature plate resiliently attached to said turn-table and in operative relation to said electromagnetic coils; electromagnetic brake means in operable relation to said turn-table; and a circuit including a source of energy and a double throw switch whereby said brake means are deenergized when said coils. are energized and the latter are deenergized before the brake means are energized.

FERENZ H. FODOR. 

